1. Field of the Invention
This invention relates to a connecting fitting whereby a branch duct or pipe may be connected to and communicated with the interior of a main duct or pipe.
2. Description of Related Art
Various different forms of connecting fittings including some of the general structural and operational features of the instant invention are disclosed in U.S. Pat. Nos. 3,865,411, 3,892,049, 3,954,289, 4,030,494, 4,058,261, 4,147,382 and 4,249,758. However, these previously known forms of duct work connecting fittings may not be readily constructed of sheet material while at the same time being operable to quickly establish an airtight connection between a main duct and a branch duct.